21150.10.
(a) A new residential or commercial building project that is subject to this division shall implement all feasible and cost-effective water efficiency measures within the interior and exterior of the project.(b) If, after implementing all feasible and cost-effective water efficiency measures within the interior and exterior of the project, the residential or commercial building will result in any new residential or commercial annual water consumption, as projected by its water supplier, the project shall mitigate its projected annual water consumption, including within the interior and exterior of the project, within the same hydrologic region, through any of the following measures:
(1) Water efficiency measures including interior and exterior water conservation.
(2) Infrastructure rehabilitation resulting in reduced water loss due to leaking pipes or reduced need to flush pipe systems.
(3) Recycled water facilities.
(4) Groundwater remediation and treatment facilities.
(5) Stormwater capture facilities.
(6) Greywater systems.
(c) The mitigation measures taken pursuant to subdivision (b) shall be reviewed, approved, and monitored by the lead agency in consultation with the water supplier.
(d) For the purpose of this section,
mitigation measures shall meet all of the following criteria:
(1) At least 40 percent of the mitigation of annual water consumption shall be accomplished through projects that serve disadvantaged communities within the same hydrologic region of the proposed project.
(2) (A)Programs or projects implemented to achieve mitigation shall have a life expectancy of at least 20 years and have quantifiable results that result in the capacity to make available or decrease the demand for an amount of water equal to the projected annual water consumption of the project.
(B) Notwithstanding subparagraph (A), if the costs of implementing the programs or projects that result in
the required quantifiable result are more than 1 percent of the total price of the commercial or residential building, the new residential or commercial building project shall only be required to implement programs or projects that, in total, cost no more than 1 percent of the total price of the commercial or residential buildings and that, to the maximum extent feasible, approach the quantifiable result specified in subparagraph (A).
(C) Notwithstanding subparagraph (A), if the new residential or commercial building project only replaces an existing residential or commercial building, the project shall only be required to implement programs or projects to mitigate the amount of water consumed by the new residential or commercial building project that exceeds the annual average water consumption, for the proceeding five years, of the residential or commercial building being replaced.
(3) Programs and projects implemented to achieve the mitigation of annual water consumption shall to the extent feasible, as determined by the lead agency, minimize greenhouse gas emissions, minimize environmental impact, reduce contaminated runoff, and provide environmental benefits.
(e) Mitigation measures undertaken pursuant to subdivision (b) may be carried out in or serve affordable housing communities and projects, or public buildings, including public education facilities.
(f) Public building projects shall implement all feasible and cost-effective water efficiency required by subdivision (a) that are required by existing building standards, but shall be exempt from the mitigation requirements set forth in subdivision (b).
(g) Affordable housing projects shall implement all feasible and
cost-effective water efficiency required by subdivision (a), but shall be exempted from the mitigation requirements pursuant to subdivision (b).
(h) For the purposes of this section, the following terms shall have the following definitions:
(1) “Affordable housing project” means a housing project specified in Section 50052.5 of the Health and Safety Code.
(2) “Disadvantaged community” has the same meaning as that set forth in Section 75005.
(3) “Hydrologic region” has the same meaning as set forth in the California Water Plan developed pursuant to Part 1.5 (commencing with Section 10004) of Division 6 of the Water Code.
(4) “Public building” means a building owned and occupied by the
state, a county, a city, a regional agency, a school district, the University of California, the California State University, or a California community college district.
(i) If a lead agency, in consultation with a water supplier, determines that a local program applicable to the new residential or commercial building project achieves equivalent results in water supply reliability as, or greater results in water supply reliability than, required by this section, the lead agency may deem the new residential or commercial building project to be in compliance with this section if the building project complies with the requirements of the local program.
(j) This section does not limit a local agency’s authority to implement local programs related to water supply reliability.